Gear for sure. Maybe a few more AA? Remember that sleeper was the 2 man exclusive content for its time. So its not something you will be able to do with shit gear. For example my pally/ber/mnk barely gets damaged in the sleeper fight anymore almost fully BIS PoP with 3500AA. I dont even have to heal, the PoP sword keeps me healed. If youre SSF or trying to keep it that way, keep farming NTOV and try to unlock Luclin. Vex thal is pretty EZ, jsut boring, and you will get lots of upgrades there. YOu will have to unlock Vex Thal by doing the Luclin progression into POP. Also your rogue skips make Vex trivial, just kill bosses and collect loots. And then you can work on your POP progression too once unlocked by doing the luclin progression which is pretty EZ.